/* * PSA crypto core internal interfaces */ /* * Copyright The Mbed TLS Contributors * SPDX-License-Identifier: Apache-2.0 * * Licensed under the Apache License, Version 2.0 (the "License"); you may * not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #ifndef PSA_CRYPTO_CORE_H #define PSA_CRYPTO_CORE_H #include "mbedtls/build_info.h" #include "psa/crypto.h" #include "psa/crypto_se_driver.h" /** Constant-time buffer comparison * * \param[in] a Left-hand buffer for comparison. * \param[in] b Right-hand buffer for comparison. * \param n Amount of bytes to compare. * * \return 0 if the buffer contents are equal, non-zero otherwise */ static inline int mbedtls_psa_safer_memcmp( const uint8_t *a, const uint8_t *b, size_t n ) { size_t i; unsigned char diff = 0; for( i = 0; i < n; i++ ) diff |= a[i] ^ b[i]; return( diff ); } /** The data structure representing a key slot, containing key material * and metadata for one key. */ typedef struct { psa_core_key_attributes_t attr; /* * Number of locks on the key slot held by the library. * * This counter is incremented by one each time a library function * retrieves through one of the dedicated internal API a pointer to the * key slot. * * This counter is decremented by one each time a library function stops * accessing the key slot and states it by calling the * psa_unlock_key_slot() API. * * This counter is used to prevent resetting the key slot while the library * may access it. For example, such control is needed in the following * scenarios: * . In case of key slot starvation, all key slots contain the description * of a key, and the library asks for the description of a persistent * key not present in the key slots, the key slots currently accessed by * the library cannot be reclaimed to free a key slot to load the * persistent key. * . In case of a multi-threaded application where one thread asks to close * or purge or destroy a key while it is in used by the library through * another thread. */ size_t lock_count; /* Dynamically allocated key data buffer. * Format as specified in psa_export_key(). */ struct key_data { uint8_t *data; size_t bytes; } key; } psa_key_slot_t; /* A mask of key attribute flags used only internally. * Currently there aren't any. */ #define PSA_KA_MASK_INTERNAL_ONLY ( \ 0 ) /** Test whether a key slot is occupied. * * A key slot is occupied iff the key type is nonzero. This works because * no valid key can have 0 as its key type. * * \param[in] slot The key slot to test. * * \return 1 if the slot is occupied, 0 otherwise. */ static inline int psa_is_key_slot_occupied( const psa_key_slot_t *slot ) { return( slot->attr.type != 0 ); } /** Test whether a key slot is locked. * * A key slot is locked iff its lock counter is strictly greater than 0. * * \param[in] slot The key slot to test. * * \return 1 if the slot is locked, 0 otherwise. */ static inline int psa_is_key_slot_locked( const psa_key_slot_t *slot ) { return( slot->lock_count > 0 ); } /** Retrieve flags from psa_key_slot_t::attr::core::flags. * * \param[in] slot The key slot to query. * \param mask The mask of bits to extract. * * \return The key attribute flags in the given slot, * bitwise-anded with \p mask. */ static inline uint16_t psa_key_slot_get_flags( const psa_key_slot_t *slot, uint16_t mask ) { return( slot->attr.flags & mask ); } /** Set flags in psa_key_slot_t::attr::core::flags. * * \param[in,out] slot The key slot to modify. * \param mask The mask of bits to modify. * \param value The new value of the selected bits. */ static inline void psa_key_slot_set_flags( psa_key_slot_t *slot, uint16_t mask, uint16_t value ) { slot->attr.flags = ( ( ~mask & slot->attr.flags ) | ( mask & value ) ); } /** Turn on flags in psa_key_slot_t::attr::core::flags. * * \param[in,out] slot The key slot to modify. * \param mask The mask of bits to set. */ static inline void psa_key_slot_set_bits_in_flags( psa_key_slot_t *slot, uint16_t mask ) { slot->attr.flags |= mask; } /** Turn off flags in psa_key_slot_t::attr::core::flags. * * \param[in,out] slot The key slot to modify. * \param mask The mask of bits to clear. */ static inline void psa_key_slot_clear_bits( psa_key_slot_t *slot, uint16_t mask ) { slot->attr.flags &= ~mask; } #if defined(MBEDTLS_PSA_CRYPTO_SE_C) /** Get the SE slot number of a key from the key slot storing its description. * * \param[in] slot The key slot to query. This must be a key slot storing * the description of a key of a dynamically registered * secure element, otherwise the behaviour is undefined. */ static inline psa_key_slot_number_t psa_key_slot_get_slot_number( const psa_key_slot_t *slot ) { return( *( (psa_key_slot_number_t *)( slot->key.data ) ) ); } #endif /** Completely wipe a slot in memory, including its policy. * * Persistent storage is not affected. * * \param[in,out] slot The key slot to wipe. * * \retval #PSA_SUCCESS * Success. This includes the case of a key slot that was * already fully wiped. * \retval #PSA_ERROR_CORRUPTION_DETECTED */ psa_status_t psa_wipe_key_slot( psa_key_slot_t *slot ); /** Try to allocate a buffer to an empty key slot. * * \param[in,out] slot Key slot to attach buffer to. * \param[in] buffer_length Requested size of the buffer. * * \retval #PSA_SUCCESS * The buffer has been successfully allocated. * \retval #PSA_ERROR_INSUFFICIENT_MEMORY * Not enough memory was available for allocation. * \retval #PSA_ERROR_ALREADY_EXISTS * Trying to allocate a buffer to a non-empty key slot. */ psa_status_t psa_allocate_buffer_to_slot( psa_key_slot_t *slot, size_t buffer_length ); /** Wipe key data from a slot. Preserves metadata such as the policy. */ psa_status_t psa_remove_key_data_from_memory( psa_key_slot_t *slot ); /** Copy key data (in export format) into an empty key slot. * * This function assumes that the slot does not contain * any key material yet. On failure, the slot content is unchanged. * * \param[in,out] slot Key slot to copy the key into. * \param[in] data Buffer containing the key material. * \param data_length Size of the key buffer. * * \retval #PSA_SUCCESS * The key has been copied successfully. * \retval #PSA_ERROR_INSUFFICIENT_MEMORY * Not enough memory was available for allocation of the * copy buffer. * \retval #PSA_ERROR_ALREADY_EXISTS * There was other key material already present in the slot. */ psa_status_t psa_copy_key_material_into_slot( psa_key_slot_t *slot, const uint8_t *data, size_t data_length ); /** Convert an mbed TLS error code to a PSA error code * * \note This function is provided solely for the convenience of * Mbed TLS and may be removed at any time without notice. * * \param ret An mbed TLS-thrown error code * * \return The corresponding PSA error code */ psa_status_t mbedtls_to_psa_error( int ret ); /** Get Mbed TLS cipher information given the cipher algorithm PSA identifier * as well as the PSA type and size of the key to be used with the cipher * algorithm. * * \param alg PSA cipher algorithm identifier * \param key_type PSA key type * \param key_bits Size of the key in bits * \param[out] cipher_id Mbed TLS cipher algorithm identifier * * \return The Mbed TLS cipher information of the cipher algorithm. * \c NULL if the PSA cipher algorithm is not supported. */ const mbedtls_cipher_info_t *mbedtls_cipher_info_from_psa( psa_algorithm_t alg, psa_key_type_t key_type, size_t key_bits, mbedtls_cipher_id_t *cipher_id ); /** Import a key in binary format. * * \note The signature of this function is that of a PSA driver * import_key entry point. This function behaves as an import_key * entry point as defined in the PSA driver interface specification for * transparent drivers. * * \param[in] attributes The attributes for the key to import. * \param[in] data The buffer containing the key data in import * format. * \param[in] data_length Size of the \p data buffer in bytes. * \param[out] key_buffer The buffer to contain the key data in output * format upon successful return. * \param[in] key_buffer_size Size of the \p key_buffer buffer in bytes. This * size is greater or equal to \p data_length. * \param[out] key_buffer_length The length of the data written in \p * key_buffer in bytes. * \param[out] bits The key size in number of bits. * * \retval #PSA_SUCCESS The key was imported successfully. * \retval #PSA_ERROR_INVALID_ARGUMENT * The key data is not correctly formatted. * \retval #PSA_ERROR_NOT_SUPPORTED * \retval #PSA_ERROR_INSUFFICIENT_MEMORY * \retval #PSA_ERROR_CORRUPTION_DETECTED */ psa_status_t psa_import_key_into_slot( const psa_key_attributes_t *attributes, const uint8_t *data, size_t data_length, uint8_t *key_buffer, size_t key_buffer_size, size_t *key_buffer_length, size_t *bits ); /** Export a key in binary format * * \note The signature of this function is that of a PSA driver export_key * entry point. This function behaves as an export_key entry point as * defined in the PSA driver interface specification. * * \param[in] attributes The attributes for the key to export. * \param[in] key_buffer Material or context of the key to export. * \param[in] key_buffer_size Size of the \p key_buffer buffer in bytes. * \param[out] data Buffer where the key data is to be written. * \param[in] data_size Size of the \p data buffer in bytes. * \param[out] data_length On success, the number of bytes written in * \p data * * \retval #PSA_SUCCESS The key was exported successfully. * \retval #PSA_ERROR_NOT_SUPPORTED * \retval #PSA_ERROR_COMMUNICATION_FAILURE * \retval #PSA_ERROR_HARDWARE_FAILURE * \retval #PSA_ERROR_CORRUPTION_DETECTED * \retval #PSA_ERROR_STORAGE_FAILURE * \retval #PSA_ERROR_INSUFFICIENT_MEMORY */ psa_status_t psa_export_key_internal( const psa_key_attributes_t *attributes, const uint8_t *key_buffer, size_t key_buffer_size, uint8_t *data, size_t data_size, size_t *data_length ); /** Export a public key or the public part of a key pair in binary format. * * \note The signature of this function is that of a PSA driver * export_public_key entry point. This function behaves as an * export_public_key entry point as defined in the PSA driver interface * specification. * * \param[in] attributes The attributes for the key to export. * \param[in] key_buffer Material or context of the key to export. * \param[in] key_buffer_size Size of the \p key_buffer buffer in bytes. * \param[out] data Buffer where the key data is to be written. * \param[in] data_size Size of the \p data buffer in bytes. * \param[out] data_length On success, the number of bytes written in * \p data * * \retval #PSA_SUCCESS The public key was exported successfully. * \retval #PSA_ERROR_NOT_SUPPORTED * \retval #PSA_ERROR_COMMUNICATION_FAILURE * \retval #PSA_ERROR_HARDWARE_FAILURE * \retval #PSA_ERROR_CORRUPTION_DETECTED * \retval #PSA_ERROR_STORAGE_FAILURE * \retval #PSA_ERROR_INSUFFICIENT_MEMORY */ psa_status_t psa_export_public_key_internal( const psa_key_attributes_t *attributes, const uint8_t *key_buffer, size_t key_buffer_size, uint8_t *data, size_t data_size, size_t *data_length ); /** * \brief Generate a key. * * \note The signature of the function is that of a PSA driver generate_key * entry point. * * \param[in] attributes The attributes for the key to generate. * \param[out] key_buffer Buffer where the key data is to be written. * \param[in] key_buffer_size Size of \p key_buffer in bytes. * \param[out] key_buffer_length On success, the number of bytes written in * \p key_buffer. * * \retval #PSA_SUCCESS * The key was generated successfully. * \retval #PSA_ERROR_INVALID_ARGUMENT * \retval #PSA_ERROR_NOT_SUPPORTED * Key size in bits or type not supported. * \retval #PSA_ERROR_BUFFER_TOO_SMALL * The size of \p key_buffer is too small. */ psa_status_t psa_generate_key_internal( const psa_key_attributes_t *attributes, uint8_t *key_buffer, size_t key_buffer_size, size_t *key_buffer_length ); /** Sign a message with a private key. For hash-and-sign algorithms, * this includes the hashing step. * * \note The signature of this function is that of a PSA driver * sign_message entry point. This function behaves as a sign_message * entry point as defined in the PSA driver interface specification for * transparent drivers. * * \note This function will call the driver for psa_sign_hash * and go through driver dispatch again. * * \param[in] attributes The attributes of the key to use for the * operation. * \param[in] key_buffer The buffer containing the key context. * \param[in] key_buffer_size Size of the \p key_buffer buffer in bytes. * \param[in] alg A signature algorithm that is compatible with * the type of the key. * \param[in] input The input message to sign. * \param[in] input_length Size of the \p input buffer in bytes. * \param[out] signature Buffer where the signature is to be written. * \param[in] signature_size Size of the \p signature buffer in bytes. * \param[out] signature_length On success, the number of bytes * that make up the returned signature value. * * \retval #PSA_SUCCESS * \retval #PSA_ERROR_BUFFER_TOO_SMALL * The size of the \p signature buffer is too small. You can * determine a sufficient buffer size by calling * #PSA_SIGN_OUTPUT_SIZE(\c key_type, \c key_bits, \p alg) * where \c key_type and \c key_bits are the type and bit-size * respectively of the key. * \retval #PSA_ERROR_NOT_SUPPORTED * \retval #PSA_ERROR_INVALID_ARGUMENT * \retval #PSA_ERROR_INSUFFICIENT_MEMORY * \retval #PSA_ERROR_CORRUPTION_DETECTED * \retval #PSA_ERROR_INSUFFICIENT_ENTROPY */ psa_status_t psa_sign_message_builtin( const psa_key_attributes_t *attributes, const uint8_t *key_buffer, size_t key_buffer_size, psa_algorithm_t alg, const uint8_t *input, size_t input_length, uint8_t *signature, size_t signature_size, size_t *signature_length ); /** Verify the signature of a message with a public key, using * a hash-and-sign verification algorithm. * * \note The signature of this function is that of a PSA driver * verify_message entry point. This function behaves as a verify_message * entry point as defined in the PSA driver interface specification for * transparent drivers. * * \note This function will call the driver for psa_verify_hash * and go through driver dispatch again. * * \param[in] attributes The attributes of the key to use for the * operation. * \param[in] key_buffer The buffer containing the key context. * \param[in] key_buffer_size Size of the \p key_buffer buffer in bytes. * \param[in] alg A signature algorithm that is compatible with * the type of the key. * \param[in] input The message whose signature is to be verified. * \param[in] input_length Size of the \p input buffer in bytes. * \param[in] signature Buffer containing the signature to verify. * \param[in] signature_length Size of the \p signature buffer in bytes. * * \retval #PSA_SUCCESS * The signature is valid. * \retval #PSA_ERROR_INVALID_SIGNATURE * The calculation was performed successfully, but the passed * signature is not a valid signature. * \retval #PSA_ERROR_NOT_SUPPORTED * \retval #PSA_ERROR_INVALID_ARGUMENT * \retval #PSA_ERROR_INSUFFICIENT_MEMORY */ psa_status_t psa_verify_message_builtin( const psa_key_attributes_t *attributes, const uint8_t *key_buffer, size_t key_buffer_size, psa_algorithm_t alg, const uint8_t *input, size_t input_length, const uint8_t *signature, size_t signature_length ); /** Sign an already-calculated hash with a private key. * * \note The signature of this function is that of a PSA driver * sign_hash entry point. This function behaves as a sign_hash * entry point as defined in the PSA driver interface specification for * transparent drivers. * * \param[in] attributes The attributes of the key to use for the * operation. * \param[in] key_buffer The buffer containing the key context. * \param[in] key_buffer_size Size of the \p key_buffer buffer in bytes. * \param[in] alg A signature algorithm that is compatible with * the type of the key. * \param[in] hash The hash or message to sign. * \param[in] hash_length Size of the \p hash buffer in bytes. * \param[out] signature Buffer where the signature is to be written. * \param[in] signature_size Size of the \p signature buffer in bytes. * \param[out] signature_length On success, the number of bytes * that make up the returned signature value. * * \retval #PSA_SUCCESS * \retval #PSA_ERROR_BUFFER_TOO_SMALL * The size of the \p signature buffer is too small. You can * determine a sufficient buffer size by calling * #PSA_SIGN_OUTPUT_SIZE(\c key_type, \c key_bits, \p alg) * where \c key_type and \c key_bits are the type and bit-size * respectively of the key. * \retval #PSA_ERROR_NOT_SUPPORTED * \retval #PSA_ERROR_INVALID_ARGUMENT * \retval #PSA_ERROR_INSUFFICIENT_MEMORY * \retval #PSA_ERROR_CORRUPTION_DETECTED * \retval #PSA_ERROR_INSUFFICIENT_ENTROPY */ psa_status_t psa_sign_hash_builtin( const psa_key_attributes_t *attributes, const uint8_t *key_buffer, size_t key_buffer_size, psa_algorithm_t alg, const uint8_t *hash, size_t hash_length, uint8_t *signature, size_t signature_size, size_t *signature_length ); /** * \brief Verify the signature a hash or short message using a public key. * * \note The signature of this function is that of a PSA driver * verify_hash entry point. This function behaves as a verify_hash * entry point as defined in the PSA driver interface specification for * transparent drivers. * * \param[in] attributes The attributes of the key to use for the * operation. * \param[in] key_buffer The buffer containing the key context. * \param[in] key_buffer_size Size of the \p key_buffer buffer in bytes. * \param[in] alg A signature algorithm that is compatible with * the type of the key. * \param[in] hash The hash or message whose signature is to be * verified. * \param[in] hash_length Size of the \p hash buffer in bytes. * \param[in] signature Buffer containing the signature to verify. * \param[in] signature_length Size of the \p signature buffer in bytes. * * \retval #PSA_SUCCESS * The signature is valid. * \retval #PSA_ERROR_INVALID_SIGNATURE * The calculation was performed successfully, but the passed * signature is not a valid signature. * \retval #PSA_ERROR_NOT_SUPPORTED * \retval #PSA_ERROR_INVALID_ARGUMENT * \retval #PSA_ERROR_INSUFFICIENT_MEMORY */ psa_status_t psa_verify_hash_builtin( const psa_key_attributes_t *attributes, const uint8_t *key_buffer, size_t key_buffer_size, psa_algorithm_t alg, const uint8_t *hash, size_t hash_length, const uint8_t *signature, size_t signature_length ); /** * \brief Validate the key bit size for unstructured keys. * * \note Check that the bit size is acceptable for a given key type for * unstructured keys. * * \param[in] type The key type * \param[in] bits The number of bits of the key * * \retval #PSA_SUCCESS * The key type and size are valid. * \retval #PSA_ERROR_INVALID_ARGUMENT * The size in bits of the key is not valid. * \retval #PSA_ERROR_NOT_SUPPORTED * The type and/or the size in bits of the key or the combination of * the two is not supported. */ psa_status_t psa_validate_unstructured_key_bit_size( psa_key_type_t type, size_t bits ); #endif /* PSA_CRYPTO_CORE_H */